I worked that door for about a decade, and got pretty comfortable with its operation.
The door is a Diebold Wedge lock, and was installed prior to my coming on board with Diebold in 85. It was lowered down through the top of the , what is now the fountain in the middle of the traffic circle on the ground level.
There are actually 2 vault doors down there, one is the emergency wedge lock, a 24×24″ which can be used if the main door is locked out.
I’ve had to replace the main wedge’s ball bearing and tracks, motors and re-wired the rotary airlock drums after they malfunctioned.
Massive 24 ton door, hydraulically operated, a real sweet piece of vault art you just dont see any more.